The questions becomes, what do you do with them?
Selling them is a fairly common option. Of course, you'll never get anywhere near what you paid for it, plus, you have to remember to factory reset the device so some stranger doesn't end up with your Flikster password information.
So, maybe selling them isn't the best option for everyone. Which is probably why we all have boxes, bags and drawers full of old phones.
Fortunately, if you don't want to sell there are some viable options. Like making it into a dashcam:
Plugging and unplugging, mounting and unmounting can be a pain. So if you have an old smartphone, make it your permanent dashcam by plugging it into a power source, mounting it and downloading an app like Autoboy Dash Cam.
or home security:
Popular Mechanics has a very cool article with some nifty ideas for getting further use out of your old smartphones without the hassle of having to sell them to strangers. Read the entire article here and let us know if they missed any in the Comments below!